Triple-Negative Breast Cancer: Correlation between MR Imaging and Pathologic Findings

Purpose: To retrospectively evaluate the magnetic resonance (MR) imaging findings of “triple-negative” breast cancer (ie, cancer that is estrogen receptor [ER] negative, progesterone receptor [PR] negative, and human epidermal growth factor receptor 2 [HER2] negative) and to compare them with those of breast cancers that are ER positive, PR positive, and HER2 negative. Materials and Methods: Institutional review board approval and informed consent were obtained. The MR imaging findings in 176 randomly assigned women (mean age, 56 years; range, 29–87 years) with surgically confirmed triple-negative breast cancers (n = 59) or ER-positive/PR-positive/HER2-negative breast cancers (n = 117) were reviewed. MR imaging findings included tumor shape, margin, internal enhancement, and size, as well as intratumoral signal intensity that was stronger than or almost the same as that of water or vessels on T2-weighted MR images. The MR imaging findings were compared with the pathologic findings. Results: High histologic grade (P < .001), unifocal lesion (P = .012), mass lesion type (P < .001), smooth mass margin (P = .001), rim enhancement (P < .001), persistent enhancement pattern (P = .005), and very high intratumoral signal intensity on T2-weighted MR images (P = .002) were significantly associated with triple-negative breast cancer. Very high intratumoral signal intensity on T2-weighted MR images was significantly associated with intratumoral necrosis (P < .001). Conclusion: Several MR imaging features might be used for detecting triple-negative breast cancer. © RSNA, 2009